class_docstr: Mixin to provide interface to work with croniter.
class_docstr_tok: ["Mixin","to","provide","interface","to","work","with","croniter","."]
code: def __init__(
      self, cron: str, timezone: str | Timezone | FixedTimezone
  ) -> None:
      self._expression = cron_presets.get(cron, cron)
  
      if isinstance(timezone, str):
          timezone = parse_timezone(timezone)
      self._timezone = timezone
  
      try:
          descriptor = ExpressionDescriptor(
              expression=self._expression,
              casing_type=CasingTypeEnum.Sentence,
              use_24hour_time_format=True,
          )
          # checking for more than 5 parameters in Cron and avoiding evaluation for now,
          # as Croniter has inconsistent evaluation with other libraries
          if len(croniter(self._expression).expanded) > 5:
              raise FormatException()
          interval_description: str = descriptor.get_description()
      except (
          CroniterBadCronError,
          FormatException,
          MissingFieldException,
      ):
          interval_description = ""
      self.description: str = interval_description
  
file_path: airflow/airflow/timetables/_cron.py
imports: from __future__ import annotations
  import datetime
  from typing import TYPE_CHECKING, Any
  from cron_descriptor import CasingTypeEnum, ExpressionDescriptor, FormatException, MissingFieldException
  from croniter import CroniterBadCronError, CroniterBadDateError, croniter
  from airflow.exceptions import AirflowTimetableInvalid
  from airflow.utils.dates import cron_presets
  from airflow.utils.timezone import convert_to_utc, make_aware, make_naive, parse_timezone
label_desc: Use image node_id 1 to create a new CronMixin object  with example: obj = CronMixin(cron, timezone)